patch - crossover, whats the difference?

Hecate

whilst out looking at network cables today I found that 2 distinct types seemed to be on sale, patch and crossover cables.

Whats the difference between these two flavours?, does each serve a specific purpose?

chernobyl

one is for direct connection (ie) pc 2 pc and the other is if you have a hub.

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Britany Spears Looking incredible

moist

To elaborate slightly, the port in NICS, hubs switches and the like are wired differently so that you just need a straight through cable.
i.e 1 -> 1, 2 -> 2, 3 -> 3, which is called a patch.
However when you are trying to connect two machines of the same type, PC -> PC, switch -> switch, and such you need a crossover which
has a few wires crossed to allow them talk.
AFAIR hubs and switches have an 'X' marked beside their port, PC's and routers don't so if your connecting an 'X' to a 'Non X',
you use a straight through or 'patch, but if your connecting an 'X' to an 'X' or a 'Non X' to a 'Non X' you need a crossover.

Thre now, I've probably confussed the issure more

Hecate

ah thats grand, just to make sure I dont buy the wrong thing.

Jaden

FYI


As Read from non-clip side (contact side).

Patch cable layout:

White of Orange
Orange
White of Green
Blue
White of Blue
Green
White of Brown
Brown

Same on each end.

For a crossover cable, as above, but with a different layout on the opposite end.

White of Green
Green
White of Orange
Blue
White of Blue
Orange
White of Brown
Brown


Other colour schemes will work, but the cable is twisted to give the above combination as optimum.

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Hail To The King, Baby.

Jaden.
Mail: jaden@eircom.net

Gladiator

i think you have to use crossover when connecting a hub to another hub or routher also, but dont quote me on that

Jaden

PC to PC = Crossover cable.
PC to Hub/Router = Patch cable.
Server to Hub/Router = Crossover cable.
Hub/Router to Hub/Router = Crossover cable.

Most hubs have a crossover port (uplink port) that allows you to use a standard patch lead. This port already has the relavant lines crossed over, thereby negating the need for a crossover cable. Alot of hubs have a port that can be either normal or uplink, selectable by a switch.

An X (as in crossover) is usually used to show an uplink port.

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Hail To The King, Baby.

Jaden.
Mail: jaden@eircom.net

Loomer

Found this - looks pretty good.

http://www.datacottage.com/

All you need to know about network cabling

WhiteWashMan

as far as i can remember, patch is just normal cable that you connect pc to hubs with, or into a wall, or patch
a crossover cable cable has 2 wires switched. i think its the communication, or ready to transmitt wires or something. basically it means that you fool the pcs into thinking that they are on a working network and therefor can send data.
must look that up again.
is a crossover cable the same as a null modem cable then? or whatever they are called, as i know they use the serial port.
maybe im talking complete b0llox!

Jaden

They are more or less the same thing.

On a crossover cable, the CTS (clear to send) and RTS (ready to send) lines are "crossed over". That is, that the CTS of one machine is connected to the RTS of the other. This effectively by-passes the handshaking protocols, and fools each machine into thinking it's connected to a server. So data can then be transmitted.

Null modem cables have the Tx (transmit) and Rx (Recieve) lines crossed over, thereby allowing data to be sent from one device to the other. If they weren't swopped, the Transmit line would be talking in both directions, and nothing would be happening on the Recieve line.

Capiche?

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Hail To The King, Baby.

Jaden.
Mail: jaden@eircom.net

Ba$tard

A X-over cable is Trasmit and Recieve reversed on one side of a cable, exactly what a hub/switch does

It switches Pin outs;
1 --> 3
2 --> 6

So the transmit on NIC1 end is the recieve on NIC2 end...

Peasy..

Ba$tard

WhiteWashMan

well look at that.
i did learn something

Renton

I made this to make it a little easier to understand, for anyone who wants to crimp their own cable.





RentZ